A network operator or technician monitoring and controlling a network typically relies on a number of key metrics to interpret the behaviour of the network, and if necessary make corrective or optimising reconfigurations of the network. Typically the network operator will receive alerts when certain operating parameters become critical, for example that one of the nodes is currently congested and is dropping packets. The network may then be reconfigured for example to route more traffic away from the congested node. A large practical network may have many hundreds or even thousands of nodes so that the task of monitoring these and adjusting the network may require a dedicated team of specialists. Typically however problems with network operation are only identified once they become critical and so management of the network is reactive. Furthermore the causes of a problem with one aspect of the network may not always be apparent, and may be due to sub-critical problems in other areas of the network which cannot normally be easily identified.